Temporomandibular disorders and autonomic dysfunction: Exploring the possible link between the two using a questionnaire survey.

OBJECTIVE: To assess autonomic function and investigate factors related to its dysfunction in patients with temporomandibular disorders (TMD) from a biopsychosocial perspective. METHODS: Seventy-six patients with TMD were investigated by clinical examination and questionnaires concerning biopsychosocial aspects (The Brief Pain Inventory, the Pain Catastrophizing Scale, and the Symptom Checklist-90-Revised) and autonomic dysfunction (The COMPASS 31). RESULTS: Seventy-one patients were included in the study. The result of multiple regression analysis showed that four variables (sex, depression, age, and pain interference) were significantly associated with autonomic dysfunction. Increased orthostatic intolerance and bladder dysfunction were observed in females and males, respectively. Younger age was associated with higher orthostatic intolerance, while higher pain interference was associated with higher secretomotor dysfunction and bladder dysfunction. Further, higher depression scores were linked to higher scores in the gastrointestinal subdomain. CONCLUSION: Autonomic dysfunction may affect TMD-related pain in the context of a biopsychosocial perspective.

Principal component analysis of the biopsychosocial features relevant to temporomandibular disorders.

OBJECTIVES: This study aimed to explore the dimensionality of three biopsychosocial constructs with multiple subdimensions, including the Symptom Checklist-90-Revised (SCL-90R), pain catastrophizing scale (PCS) and Pittsburgh Sleep Quality Index (PSQI), and to identify the latent dimensions of five biopsychosocial constructs (SCL-90R, PCS, PSQI, pain severity, and pain interference) using the principal component analysis (PCA) in patients with temporomandibular disorder (TMD). SUBJECTS AND METHODS: A secondary analysis of a previous cross-sectional study comprising 1488 patients with painful TMD was conducted using multiple questionnaires. RESULTS: PCA of the SCL-90R and PCS identified one factor, which explained 60.8% and 80.2% of the total variance, respectively. For the PSQI, three factors explained 61.3% of the variance. PCA resulted in two main orthogonal components: factor 1, which comprised a combination of scores for pain severity, pain interference and global scores of PCS, and PSQI; and factor 2, which comprised one measure of the SCL-90R. Factors 1 (46.5%) and 2 (20.0%) explained 66.5% of the total variance. CONCLUSION: The findings of this study revealed that five measures can be primarily categorised into two latent constructs of the psychological (affective) and pain-related (sensory-cognitive) dimensions. These core components could be applied in clinical settings and for research purposes.

Relevance of sleep, pain cognition, and psychological distress with regard to pain in patients with burning mouth syndrome.

Objective: To clarify the influence of sleep, psychological distress, and pain catastrophizing on the pain experience in patients with burning mouth syndrome (BMS).Methods: Ninety-three patients with BMS were investigated by reviewing medical records and questionnaires using the Brief Pain Inventory (BPI), Pittsburgh Sleep Quality Index (PSQI), Symptom Checklist-90 revised (SCL-90R), and pain catastrophizing scale (PCS).Results: Of the 65 patients included in the study, 81.5% and 66% showed high PSQI and PCS scores, respectively. The PSQI, PCS, and SCL-90R scores correlated positively with pain interference. The result of multiple regression analysis demonstrated that helplessness and rumination of PCS significantly add to the prediction of pain interference.Discussion: Pain catastrophizing rather than psychological distress and sleep quality seems to be associated with pain experience in patients with BMS. Therefore, targeting pain catastrophizing, specifically rumination and helplessness, might lead to reduction of pain-related disability in BMS patients.

Disturbed sleep may be a core risk factor for jaw functional limitation in patients with painful temporomandibular disorders.

BACKGROUND: Pain related to temporomandibular disorder (TMD) usually affects jaw function. In patients with TMD, little is known about the biopsychosocial relevance to jaw functional limitations. OBJECTIVE: This study explored the impact of biopsychosocial risk factors on jaw functional limitation in patients with painful TMD. METHODS: A comprehensive set of patient-reported outcomes (PROs), consisting of pain severity (Brief Pain Inventory), psychological stress (Symptom Checklist-90-Revised), catastrophising thought (Pain Catastrophizing Scale), kinesiophobia (Tampa Scale for Kinesiophobia-TMD), sleep quality (Pittsburgh Sleep Quality Index) and jaw functional limitation (Jaw Functional Limitation Scale-20), were administered, and clinical examinations were performed in patients with TMD. RESULTS: This study included the data obtained from 131 patients with painful TMD. In the logistic regression analysis, biomedical factors (age, sex, pain duration and TMD phenotype) were not associated with jaw functional limitation. Correlations were higher in the order of sleep quality (ρ = 0.946), pain severity (ρ = 0.582), pain catastrophising (ρ = 0.535), kinesiophobia (ρ = 0.486) and emotional distress (ρ = 0.268). Multiple regression analysis demonstrated three predictors, including pain severity (p = .001), kinesiophobia (p = .023) and sleep quality (p < .001) for jaw functional limitation. In the mediation analysis, the indirect effect of pain severity on the association between sleep and limitation was significant (p < .0001). CONCLUSION: Jaw functional limitation is associated with biopsychosocial factors. In particular, sleep may be a core risk factor for functional limitation in patients with painful TMD.

Phenotyping 1488 patients with painful temporomandibular disorders and its relevance to subjective sleep quality: A key step for stratified medicine.

Objective: To investigate biopsychosocial characteristics and sleep quality among three TMD phenotypes and to identify the influential factors on sleep quality among those patients.Methods: Retrospective data from chart review and self-reported questionnaires included demographics, the Brief Pain Inventory, the Pain CatastropPain Prospective Evaluation and Risk Assessmenthizing Scale, the Symptom Check List-90 Revised, and the Pittsburgh Sleep Quality Index.Results: A total of 1488 patients with painful TMD (female, 63.8%) were included and stratified into three groups: joint pain (n = 570), muscle pain (n = 542), and joint-muscle combined pain (n = 376). There were significant differences among demographic characteristics, pain experience, pain catastrophizing, and psychological distress of the three groups. Poor sleep quality presented in 78.4% of all patients. Sleep quality was significantly associated with TMD phenotypes, sex, and a helplessness component of pain catastrophizing.Discussion: This patient-centered and stratified approach will allow clinicians to come one step closer to personalized medicine.

Profiling thermal pain using quantitative sensory testing in patients with trigeminal nerve injury.

OBJECTIVES: To investigate the thermal pain phenotypes using QST in patients with unilateral trigeminal nerve injury and to explore whether these different thermal pain phenotypes are associated with clinical and psychophysical characteristics. METHODS: This retrospective study included 84 patients diagnosed with posttraumatic trigeminal neuropathy involving inferior alveolar nerve (IAN) and lingual nerve (LN). Data on clinical characteristics, subjective symptoms including hypoesthesia, dysesthesia, and allodynia, and objective signs using thermal QST were collected and explored. RESULTS: Three heat (heat hypoalgesia, heat hyperalgesia, and within normal range) and cold pain phenotypes (cold hypoalgesia, cold hyperalgesia, and within normal ranges) were identified, respectively. Thermal hypoalgesia was more frequently observed than thermal hyperalgesia. Heat hypoalgesia regardless of cold pain abnormalities appears to be associated with subjective negative symptoms, while thermal hyperalgesia seems to have little relationship with negative and positive symptoms. Thermal pain phenotypes were associated with loss of innocuous thermal sensation. Unlike heat pain phenotypes, cold pain phenotypes differed between IAN injury and LN injury. CONCLUSION: The thermal pain phenotypes identified in this study seem to be related to clinical and psychophysical findings differently. These results would be a good starting point for assessing posttraumatic trigeminal neuropathy and interpreting the thermal QST results.

Quantitative and qualitative sensory testing results are associated with numbness rather than neuropathic pain in patients with post-implant trigeminal neuropathy: a cross-sectional pilot study.

Purpose: This study aimed to characterize the sensory profile of patients with post-implant trigeminal neuropathy and identify the association between subjective symptoms and objective signs including psychophysical testing and radiographic imaging. This study further evaluated to the association between quantitative sensory testing (QST)/qualitative sensory testing (QualST) and the severity of nerve injury graded by radiographic imaging. Materials and methods: This retrospective study included 34 patients diagnosed with post-implant trigeminal neuropathy. Data on the neuropathic pain symptom inventory (NPSI), thermal and electric QST, bedside QualST, and cone beam computed tomography (CBCT) was collected and the association between these variables were analysed. Results: Numbness was the most common subjective symptom and evoked pain was the most frequent neuropathic pain. There was no significant correlation between negative and positive symptoms. Spearman's rank correlation analyses indicated that objective findings including QST/QualST correlated with a sensory loss profile rather than a gain of function profile. Moderate positive correlations between some positive symptoms and the score of QualST were observed. The Mann-Whitney U test showed that subjective symptoms did not differ according to the severity of nerve damage according to CBCT, but the electric QST and QualST was discriminative. Conclusions: This study suggests that QST/QualST associated with the severity of nerve damage according to CBCT might be useful in assessing numbness in patients with negative and positive symptoms after implant surgery, but may be of marginal utility in the evaluation of neuropathic pain within the limitation of this cross-sectional study with small sample size.

Pain Catastrophizing Mediates the Effects of Psychological Distress on Pain Interference in Patients with Orofacial Pain: A Cross-Sectional Study.

AIMS: To investigate whether pain catastrophizing has not only direct effects as a predictor of pain-related interference but also indirect effects as a mediator in the relationship between psychological distress and pain interference and to examine the mediating roles of subtypes of catastrophizing (magnification, rumination, and helplessness) between psychological distress and interference. METHODS: This retrospective study included 815 patients with orofacial pain aged 18 to 81 years. All participants completed a set of self-administered questionnaires concerning pain interference (Brief Pain Inventory), psychological distress (Symptom Checklist-90-Revised), and pain catastrophizing (Pain Catastrophizing Scale) at the first consultation. The associations between these three variables were calculated using mediation path analysis. RESULTS: Pain catastrophizing predicted pain interference. In addition, 34% of the variance in pain interference attributable to psychological distress was mediated by catastrophizing when controlling for pain duration and severity. The greatest portion of the mediating effect of catastrophizing was attributable to the helplessness component. CONCLUSION: Within the limitations of cross-sectional studies, this study demonstrated that pain catastrophizing mediates the effects of psychological distress on pain interference in patients with orofacial pain. Most of the mediating effects were attributable to the helplessness component of pain catastrophizing. Cognitive behavioral therapy targeting pain catastrophizing, specifically helplessness, could potentially reduce pain-related disability in orofacial pain patients.

Comparison of unpleasant and pain thresholds of thermal stimuli in the orofacial regions: a psychophysical study using quantitative sensory testing in healthy young men.

Purpose/Aim: To gain a better understanding of the psychophysics of thermal pain perception in a clinical setting, this study investigated whether thermal thresholds of unpleasantness are different from pain thresholds of cold and heat stimuli. Of particular interest was the relationship between unpleasantness and pain thresholds for cold vs heat stimuli. MATERIAL AND METHODS: Thirty healthy male volunteers (mean age 26.1 years, range 23 to 32 years) participated. Thermal detection, cold pain (CPT) and heat pain (HPT) thresholds were measured at 5 trigeminal sites by the method of limits using quantitative sensory testing (QST), followed by cold unpleasant (CUT) and heat unpleasant (HUT) thresholds. RESULTS: The temperatures at which individuals first reported thermal sensations as unpleasant or painful substantially differed among subjects. CUT exhibited a higher mean value with less variability than CPT, and HUT presented a lower mean than HPT (p < .001). As with CPT, CUT did not show any significant difference between the test sites. On the other hand, HUT, like HPT, exhibited site differences (p < .001). There was moderate correlation between CUT and CPT, whereas HUT and HPT were strongly correlated. The relationship between unpleasant and pain thresholds of cold vs heat stimuli was significantly different even when controlling for test site variability (p < .001). CONCLUSION: These findings indicate that unpleasant and pain thresholds to thermal stimuli differ in healthy young men. Of particular note is the distinct relationship of unpleasant and pain thresholds of cold vs heat stimuli, revealing the thermal difference in temperature transition from unpleasantness to pain.

Risk factors for the efficacy of oral appliance for treating obstructive sleep apnea: A preliminary study.

OBJECTIVE: To identify potential risk factors of response to oral appliance in patients with obstructive sleep apnea (OSA). METHODS: Fifteen OSA patients were enrolled. Clinical characteristics, cephalometric measurements, and the results of home sleep testing were retrospectively obtained at baseline, and a sleep test was done again at the end of treatment. RESULTS: Twelve subjects were responders and three were non-responders. The diastolic blood pressure, minimum pulse rate, SNA (Angle between sella-nasion and nasion-A point), ANB (Anteroposterior maxilla/mandible discrepancy), and facial convexity of non-responders was higher than those of responders. Unlike AHI, non-responders showed a lower lowest oxygen saturation (%) than responders. DISCUSSION: Elevated diastolic pressure and minimal pulse rate, higher skeletal convexity and lowered lowest oxygen saturation might be risk factors to oral appliance efficacy in the OSA patients. More research in a large sample is needed to verify the results of the current study.

Two-point discrimination values vary depending on test site, sex and test modality in the orofacial region: a preliminary study.

OBJECTIVE: The aims of the present study were to determine the normal values of TPD in the six trigeminal sites (the forehead, cheek, mentum, upper lip, lower lip, and the tongue tip) and to investigate the effect of the site, sex, and test modality on the TPD perception. MATERIAL AND METHODS: Forty healthy volunteers consisting of age-matched men (20) and women (20) with a mean age of 27.1 years were recruited. One examiner performed the TPD test using a simple hand-operated device, i.e., by drawing compass with a blunt or sharp-pointed tip. The static TPD with a blunt-pointed tip (STPDB), moving TPD with a blunt-pointed tip (MTPDB), and static TPD with a sharp-pointed tip (STPDS) were measured. The predictors were the site, sex, and test modality, and the outcome variable was the TPD value. Three-way ANOVA was used for statistics. RESULTS: The analysis showed a significant effect of the site, sex and test modality on the TPD values. Significant differences between the test sites were observed with the descending order from the forehead and cheek>mentum>upper lip and lower lip>tongue tip and index finger. Women showed lower TPD values than those of men. The STPDS measurements were consistently lower than those of the STPDB and MTPDB. CONCLUSIONS: The normal values of TPD in this study suggest that the cheek and forehead were less sensitive than other regions evaluated and women were more sensitive than men. The STPDS was the most sensitive test modality.

Two-point discrimination values vary depending on test site, sex and test modality in the orofacial region: a preliminary study

Abstract The two-point discrimination (TPD) test is one of the most commonly used neurosensory tests to assess mechanoperception in the clinical settings. While there have been numerous studies of functional sensibility of the hand using TPD test, there have been relatively not enough reports on TPD in the orofacial region. Objective The aims of the present study were to determine the normal values of TPD in the six trigeminal sites (the forehead, cheek, mentum, upper lip, lower lip, and the tongue tip) and to investigate the effect of the site, sex, and test modality on the TPD perception. Material and Methods Forty healthy volunteers consisting of age-matched men (20) and women (20) with a mean age of 27.1 years were recruited. One examiner performed the TPD test using a simple hand-operated device, i.e., by drawing compass with a blunt or sharp-pointed tip. The static TPD with a blunt-pointed tip (STPDB), moving TPD with a blunt-pointed tip (MTPDB), and static TPD with a sharp-pointed tip (STPDS) were measured. The predictors were the site, sex, and test modality, and the outcome variable was the TPD value. Three-way ANOVA was used for statistics. Results The analysis showed a significant effect of the site, sex and test modality on the TPD values. Significant differences between the test sites were observed with the descending order from the forehead and cheek>mentum>upper lip and lower lip>tongue tip and index finger. Women showed lower TPD values than those of men. The STPDS measurements were consistently lower than those of the STPDB and MTPDB. Conclusions The normal values of TPD in this study suggest that the cheek and forehead were less sensitive than other regions evaluated and women were more sensitive than men. The STPDS was the most sensitive test modality.

Thermal Perception as a Key Factor for Assessing Effects of Trigeminal Nerve Injury.

AIMS: To conduct a functional examination using multimodal exploration of a sample of patients with iatrogenic trigeminal nerve injury to understand the underlying mechanisms of neuropathic pain following trigeminal nerve injury. METHODS: Subjective and objective symptoms and responses to thermal and electrical quantitative sensory testing (QST) were evaluated in 85 patients with unilateral trigeminal nerve injury. Objective symptoms were measured by seven clinical sensory tests. Thermal QST included cold detection threshold (CDT), warm detection threshold (WDT), and heat pain threshold (HPT). Electrical current perception threshold was performed with electrical stimuli of 2,000, 250, and 5 Hz. The time since injury was included as a possible independent variable. The data were analyzed using chi-square test, independent t test, Mann Whitney U test, one-way analysis of variance (ANOVA), and Kruskal-Wallis test. Further analyses with Pearson correlation analysis, Spearman rank correlation analysis, and cluster analysis were applied. RESULTS: Unlike objective symptoms, thermal and electrical QST values and subjective symptoms did not improve in patients with an old injury. Thermal QST, particularly WDT, showed the highest positive correlation with subjective symptoms in all tests. Cluster analysis of the thermal QST values identified three subgroups: cluster 1, which was characterized by prominent cold and warm hypoesthesia; cluster 2, which presented elevated WDT; and cluster 3, which showed the smallest thermal differences for all thermal variables but had the highest proportion of neuropathic pain. CONCLUSION: These findings have demonstrated that thermal QST is a suitable tool for evaluating and characterizing the sensory effects of trigeminal nerve injury. Three subgroups with different thermosensory profiles showed that the less the damage, the more neuropathic pain occurs. The loss of warm perception in particular might play a pivotal role in the chronicity and severity of subjective sensory symptoms.

Influence of test site and baseline temperature on orofacial thermal thresholds.

AIMS: To investigate thermal thresholds of selected orofacial sites, determine if there is a relationship between thermal thresholds at each site, and analyze the influence of two different baseline temperatures on thermal thresholds at the tongue tip. METHODS: Thirty healthy men (mean age, 26 years) participated. Cold detection (CDT), warm detection (WDT), cold pain (CPT), and heat pain (HPT) thresholds were measured bilaterally at five orofacial sites (mentum, lower lip, cheek, forehead, and tongue tip). Relations between thermal thresholds at each test site were assessed. Thermal sensitivity of the tongue tip was compared at two different baseline temperatures (32°C and 36°C). One-way ANOVA, Turkey post-hoc test, paired t test and Pearson's correlation were used for statistical analyses. RESULTS: There was a significant difference for CDT, WDT, and HPT between test sites (ANOVA, P < .001) but no significant difference for CPT (P = .634). Subjects sensitive to cooling were sensitive to warming at the mentum (r = 0.379), tongue tip (r = 0.610), and cheek (r = 0.431) but not at the other test sites. There was a strong negative correlation between CPT and HPT at all test sites. There was no significant difference for CDT and WDT at the baseline temperature of 36°C (paired t test, P = .660), but there was a significant difference at the baseline temperature of 32°C (P < .001). There were no significant differences between CPTs at the two different baseline temperatures (P = .773), while a significant difference existed between HPTs (P = .034). CONCLUSION: Thermal thresholds varied between the orofacial test sites, and baseline temperature affected thermal sensitivity of the tongue. Subjects who were relatively sensitive to cold tended to be more sensitive to heat.

n-Butanol extracts of Panax notoginseng suppress LPS-induced MMP-2 expression in periodontal ligament fibroblasts and inhibit osteoclastogenesis by suppressing MAPK in LPS-activated RAW264.7 cells.

OBJECTIVE: Periodontitis is a group of inflammatory diseases that affect connective tissue attachments and the supporting bone that surround the teeth. Osteoclasts are responsible for skeletal modeling and remodeling but may also destroy bone in several bone diseases, including osteoporosis and periodontitis. This study examined the anti-inflammatory effects of Panax notoginseng (PN) on periodontal ligament fibroblasts (PDLFs) and RAW264.7 cells under lipopolysaccharide (LPS) induced inflammatory conditions. DESIGN: The effects of PN on PDLFs were determined by measuring the cell viability and mRNA expression of tissue-destructive proteins. The effects of PN on osteoclasts were examined by measuring the following: (1) the cell viability, (2) the formation of Tartrate-resistant acid phosphatase (TRAP)(+) multinucleated cells, (3) MAPK signaling pathways, (4) mRNA expression of inflammatory-related proteins and (5) nitric oxide (NO) production. RESULTS: The n-butanol extracts of PN (bPN) increased the cell proliferation of the PDLFs and decreased the mRNA expression of matrix metalloproteinase (MMP)-2 in the PDLFs. bPN inhibited the formation of LPS-stimulated TRAP(+) multinucleated cells. bPN also inhibited the LPS-stimulated activation of JNK and ERK signaling, and inhibited the LPS-stimulated degradation of I(K)B in the RAW264.7 cells. In addition, bPN decreased the mRNA expression of MMP-9 and iNOS, which are involved in the range of pathophysiological processes, such as inflammation in the RAW264.7 cells. NO production was also decreased via the inhibition of iNOS. CONCLUSIONS: These findings suggest that bPN has therapeutic effects on bone-destructive processes, such as those that occur in periodontal diseases.

Effects of water flow on dental hard tissue ablation using Er:YAG laser.

OBJECTIVE: The aim of this study was to investigate the effect of water on dental hard tissue ablation using Er:YAG laser as it relates to energy and pulse repetition rate, and determine the water flow rate that produces the most effective ablation at a given irradiation condition. BACKGROUND DATA: Er:YAG laser application leads to volumetric expansion and micro-explosions that result in hard tissue ablation. Ablation efficiency is improved when combined with fine water spray. MATERIALS AND METHODS: Extracted, healthy human molars were sectioned into two pieces and categorized into small groups related to water flow rate (1.69, 6.75, and 13.5 mL/min), pulse energy (250 and 400 mJ), and pulse repetition rate (5, 10, and 20 Hz). Within the combination of irradiation parameters, a laser beam was applied over enamel and dentin surfaces of the specimens, and the ablation amount was determined by differences in weight before and after irradiation. RESULTS: At a pulse energy of 250 mJ, the most effective ablation resulted from a water flow rate of 1.69 mL/min in both enamel and dentin. With 400 mJ/pulse, dentin removal was most effective at the water flow rate of 1.69 mL/min, whereas the efficiency of enamel ablation was the highest at 6.75 mL/min. Dental hard tissue ablated better as energy and pulse repetition rate increased. CONCLUSION: Effective ablation of dental hard tissue using Er:YAG laser requires that the appropriate water flow rate correspond properly to irradiation conditions. The results of this study suggest the following parameters; a water flow rate of 1.69 mL/min for enamel and dentin ablation at a pulse energy of 250 mJ and for dentin ablation at 400 mJ/pulse, and a water flow rate of 6.75 mL/min for enamel ablation at a pulse energy of 400 mJ, regardless of pulse repetition rate of 5, 10, and 20 Hz.